1. Field of the Invention
The present invention relates to a light-emitting element driving circuit and a cellular phone, and more particularly to a light-emitting element driving circuit provided in an apparatus including two substrates, and a cellular phone incorporating the light-emitting element driving circuit.
2. Description of the Related Art
If a user does not respond to an incoming call (phone call, e-mail, etc.), a cellular phone causes a light-emitting element such as a light emitting diode (LED) to perform a flickering operation to notify the user of the presence of an unattended incoming call. For example, as discussed in Japanese Laid-Open Patent Application No. 2007-108545, a light-emitting element driving apparatus installed on a portable device includes a light source unit, which includes a light-emitting element and a driving unit supplying constant drive current to the light-emitting element. Furthermore, the driving apparatus includes a control unit, which operates to control an overall system of the portable device, a battery power source capable of supplying electrical power to the light source unit and the control unit, and a charger element to be charged by the battery power source and supplying electrical power to the light source unit.